WASHINGTON — It is an old tradition, a White House dinner governed by ritual and protocol that happens to be this city’s hottest social event. But at their first state dinner Tuesday night, President Barack Obama and his wife, Michelle, made sure to infuse the glittering gala with distinctive touches.

They hired a new florist, who bedecked the tented outdoor dining room with locally grown, sustainably harvested magnolias and ivy. They selected a guest chef, Marcus Samuelsson of Aquavit in New York, a U.S. citizen who was born in Ethiopia, reared in Sweden and cooks up melting pots of flavors and cuisines.

They invited students from poor neighborhoods to witness the arrival of the guests of honor, Prime Minister Manmohan Singh of India and his wife, Gursharan Kaur, and presented a mélange of musical entertainment, including Jennifer Hudson, the singer and actress; and A.R. Rahman, the Indian composer who wrote the score to the movie “Slumdog Millionaire.”

At the tables, the meatless menu included a mix of Indian and American favorites, including some African-American standards. Collard greens and curried prawns, chick peas and okra, nan and cornbread were served to the 320 guests — including some well-known Republicans and prominent Indian-Americans — who started off with arugula from the White House garden and finished up with pumpkin pie.

The evening was a mix of politics, diplomacy and glamour, with donors mingling with lawmakers, Indian dignitaries and Hollywood celebrities decked out in tuxedos and dresses. The first lady wore a golden sleeveless gown created by Naeem Khan, an Indian-American designer.